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Import UltraRogue from the Roguelike Restoration Project (r1490)
author John "Elwin" Edwards
date Tue, 31 Jan 2017 19:56:04 -0500
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253:d9badb9c0179 256:c495a4f288c6
1 /*
2 ident.c - routines to associate an identifier with an object
3
4 UltraRogue: The Ultimate Adventure in the Dungeons of Doom
5 Copyright (C) 1986, 1991, 1993, 1995 Herb Chong
6 All rights reserved.
7
8 See the file LICENSE.TXT for full copyright and licensing information.
9 */
10
11 /*
12 * ident
13 *
14 * This file contains routines to associate an identifier with an object. The
15 * identifiers are organized by type. Once an identifier is attached to an
16 * object, it remains with that object until the object is removed from the
17 * game. The identifiers are small integers, and they are assigned merely by
18 * counting objects of the same type. Allocation picks the next available
19 * integer.
20 *
21 * It is required that the linked list be sorted within types so that gaps can
22 * easily be detected.
23 */
24
25 #include "rogue.h"
26
27 /*
28 * Index of 0 is invalid (unused state)
29 */
30
31 char print_letters[] = " abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
32 linked_list *ident_list = NULL; /* master list of all items */
33
34 /*
35 get_ident()
36
37 Gets the identifier for the given object. If an identifier exists, it is
38 returned. If not, one is allocated and returned to the user. The
39 identifier remains constant as long as the object is in the game.
40 */
41
42 int
43 get_ident(struct object *obj_p)
44 {
45 int obj_type = obj_p->o_type;
46 linked_list *list_p; /* pointer into ident_list */
47 int new_id = 1; /* in case we have to allocate */
48 struct object *tmp_obj_p;
49 struct linked_list *new_place_p = NULL;
50
51 if (identifier(obj_p) != 0)
52 return (identifier(obj_p));
53
54 /* no identifier - must allocate one */
55
56 for (list_p = ident_list; list_p != NULL; list_p = next(list_p))
57 {
58 tmp_obj_p = OBJPTR(list_p);
59
60 if (tmp_obj_p->o_type == obj_type)
61 {
62 if (identifier(tmp_obj_p) == new_id)
63 {
64 /* if this id is taken, try next */
65 new_place_p = list_p;
66 new_id++;
67 }
68 }
69 }
70
71 /*
72 * If we get here, the object is not in the list, and we need to add
73 * it. The proper id is in new_id, and the place to put it is right
74 * after new_place_p.
75 */
76
77 list_p = new_list();
78 _attach_after(&ident_list, new_place_p, list_p);
79 identifier(obj_p) = new_id;
80 list_p->data.obj = obj_p;
81 return(new_id);
82 }
83
84 /*
85 free_ident()
86
87 Frees up an identifier by removing the list entry that contains that item.
88 If the item isn't found, nothing is done.
89 */
90
91 void
92 free_ident(struct object *obj_p)
93 {
94 linked_list *list_p;
95
96 for (list_p = ident_list; list_p != NULL; list_p = next(list_p))
97 {
98 if (obj_p == OBJPTR(list_p))
99 {
100 _detach(&ident_list, list_p); /* unlink it from the list */
101 ur_free(list_p); /* release link structure */
102 break;
103 }
104 }
105 }
106
107 /*
108 unprint_id()
109
110 Converts a printable id from print_letters to the real thing by getting the
111 index.
112 */
113
114 int
115 unprint_id(char *print_id)
116 {
117 char *id_p;
118
119 for (id_p = print_letters; id_p != NULL; id_p++)
120 if (*id_p == *print_id)
121 break;
122
123 return( (int) (id_p - print_letters) );
124 }
125
126 /*
127 max_print()
128
129 returns the size of the print list
130 */
131
132 int
133 max_print(void)
134 {
135 return(sizeof(print_letters) - 2); /* 1 for blank and 1 for EOS string */
136 }